| With the deepening of China's policy of "developing large units and suppressing small ones" and the increasing capacity of power station,the working condition of thermal power generation equipment is becoming more and more severe which is required to run well in the environment of higher temperature and pressure.As major auxiliary equipment for matching turbine & boiler,Steam turbine bypass system is also faced with the improvement of working conditions.Cavitation,flashing,vibration,noise,etc.,occur more easily when valves are under severer conditions.Disc labyrinth regulating valves have solved or eased the above problems quite well,therefore in the power plant they are widely used.In this thesis,using the parameters(pressure,temperature,etc.)of TRL & VWO condition from Inner Mongolia SL-3HT power station,and referring abroad & domestic technical literature and standards,complete the calculation of disc labyrinth regulating valve's flow and choosing pressure level & basic internal diameter.Design major valve parts including body,bonnet,plug(disc stack),stem,seat and bolt.Integrate part drawings,whole valve drawing,and data sheet for major technical parameters of regulating valve.Get data analyze for speed,energy and noise according to experience.Do strength check for major pressure boundary parts includes body & bonnet according to regulating valve design manual to verify the design & safety.Set up 3D model and simulate the regulating valve by using CFD software.Get the distribution of velocity and pressure.Analyze its fluency and rationality of pressure reducing generally.Verify the regulating valve can reduce cavitation,vibration,noise and other undesirable phenomena,and has a longer service life.By numerical simulation,calculate the flow under different valve opening.Compare the simulation value and the theoretical value to verify its good regulation performance,and acquire the rules of flow,pressure,flow area,flow resistance impacted by changing valve opening. |
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